1. Field of Invention
Inventive aspects are associated with optical fiber shape sensing, more particularly to calibrating an optical fiber shape sensor to a kinematic chain, and still more particularly to calibrating an optical fiber shape sensor to steerable device in a telerobotic surgical system.
2. Art
Optical fiber shape sensors are known. See e.g., U.S. Pat. No. 5,798,521 (filed Feb. 27, 1997) (disclosing “Apparatus and Method for Measuring Strain in Bragg Gratings”), U.S. Pat. No. 6,389,187 B1 (filed Jun. 17, 1998) (disclosing “Optical Fiber Bend Sensor”), U.S. Patent Application Pub. No. US 2006/0013523 A1 (filed Jul. 13, 2005) (disclosing “Fiber Optic Position and Shape Sensing Device and Method Relating Thereto”), and Roger G. Duncan et al., Characterization of a Fiber-Optic Shape and Position Sensor, Smart Structures and Materials 2006: Smart Sensor Monitoring Systems and Applications (D. Inaudi et al. eds.), 6167 Proceedings of SPIE 616704 (Mar. 16, 2006), all of which are incorporated herein by reference. Optical fiber shape sensors have been used to sense joint angles in a minimally invasive surgical instrument. See e.g., U.S. Patent Application Pub. No. US 2007/0156019 A1 (filed Jul. 20, 2006) (disclosing “Robotic Surgery System Including Position Sensors Using Fiber Bragg Gratings”) and NASA Tech Briefs, NASA-Inspired Shape-Sensing Fibers Enable Minimally Invasive Surgery (Feb. 1, 2008), http://www.techbriefs.com/content/view/2585/ (last viewed Mar. 18, 2008), both of which are incorporated herein by reference.
When an optical fiber shape sensing system is used to determine the shape of a movable mechanical structure, and the shape information from the optical fiber is used to accurately place the mechanical structure in various poses in two or three dimensions, it is necessary to calibrate the fiber's reference frame to the mechanical structure's reference frame. Further, it is desirable to establish other useful relationships between the optical fiber and the mechanical structure that can be used to enhance control of the mechanical structure.